Virginia Republicans have amassed so much campaign cash they can claim a financial edge in virtually every tight race throughout the state as they head toward the Nov. 2 legislative elections.

From Norfolk to Northern Virginia, Republican incumbents and challengers already had a cash advantage in most of the closely watched races as October began, campaign reports show. And political action committee money controlled by Gov. James S. Gilmore III and other Republicans could tip the balance in any of those races where Democrats had the edge.

Democrats spent heavily last month to protect incumbents in danger of losing tough challenges across the state, including $74,000 to veteran state Sen. Stanley C. Walker (Norfolk), $70,000 to Del. Donald L. Williams (Norfolk) and $31,400 to state Sen. John S. Edwards (Roanoke).

The GOP financial gains reverse a historic Democratic advantage in raising money and, Republicans say, will help them to take control of the General Assembly for the first time since Reconstruction. If that happens, the party would control state government and would be in a position to redraw legislative boundaries to cement its power for the next decade.

The Republican financial advantage startled even Democrats who had expected to be outspent. Republican candidates and PACs had nearly $2 million more in cash -- $5.73 million vs. $3.77 million -- on Oct. 1, according to campaign finance reports.

"You know how to upset a guy," said Del. Kenneth R. Plum (Fairfax), chairman of the state Democratic Party, when told of the Republican advantage. "What do you want me to say? Ouch."

Republicans have enough of an edge in cash on hand to tip the financial balance of any race they choose, according to a Washington Post analysis of campaign finance reports compiled by the Virginia Public Access Project and sponsored by The Post, Virginia Commonwealth University and state news organizations.

Gilmore and others continued to raise money furiously this month. They can target key races with television and radio ads and waves of literature that reach directly into voters' mailboxes.

"We don't think we're going to take all 140 seats," said Republican Party spokesman Tim Murtaugh. "But it will not be because of a lack of money. Our candidates will have all the resources they need. It's extremely unlikely that any of our candidates will be outspent."

Driving the dollar totals are the vigorous state economy and the historic importance of the election.

Spending on legislative races has increased sharply as Republican gains made elections more competitive. Candidates spent $10 million in 1991 and $21 million in 1995. Some political experts suggest that number could nearly double again this year.

Together, candidates and PACs from both parties had spent $23.7 million through Oct. 1 and had $9.7 million in cash left over with a month of fund-raising left, according to The Post's analysis.

In Northern Virginia, state Sen. Jane H. Woods (R-Fairfax) had $125,600 -- twice as much as Democratic rival Leslie L. Byrne's $56,900 and nearly six times the cash of independent Virginia T. Dobey, who had $22,200.

"I keep hearing it's 2-1," said Robert Becker, campaign manager for Byrne, "but we're outmailing them now. . . . I think we're outcommunicating her."

In southern Fairfax County, Republican Scott T. Klein had $48,000, compared with $29,100 for Democrat Kristen J. Amundson in a race for an open House seat. Elsewhere in the county, Del. James H. Dillard II (R) had $62,700, compared with $18,900 for Democratic challenger Eileen R. Filler-Corn. Del. Roger J. McClure, considered one of the state's most vulnerable Republicans, had $51,500, compared with $2,600 for Democratic challenger James E. Mitchell III.

Democrats had an edge in a couple of races in the region. Del. Gladys B. Keating had $85,600, compared with $44,400 for Republican challenger Thomas M. Bolvin. And Republican Del. Michele B. McQuigg had $22,400, compared with $28,100 for Democratic challenger Virginia M. Stephens.

But Republicans were ready to help candidates in trouble with PAC cash totaling $1.58 million, compared with $700,000 for Democratic PACs.